X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Fthreads.c;h=73c3f3c08b649d10d62c504a17ce2de0f8ea7dcc;hb=9143c184873d0b55444dc1c1084f3e9f3f2614bf;hp=58100b696a6abf2c3f01b13ba6d18ea50bd5060b;hpb=a506fc15c09f7d8f178a7c7d9658b5bf45778128;p=tpg%2Facess2.git diff --git a/Kernel/threads.c b/Kernel/threads.c index 58100b69..73c3f3c0 100644 --- a/Kernel/threads.c +++ b/Kernel/threads.c @@ -7,10 +7,22 @@ #include #include +// Configuration +#define DEBUG_TRACE_TICKETS 0 // Trace ticket counts +#define DEBUG_TRACE_STATE 0 // Trace state changes (sleep/wake) + +// --- Schedulers --- +#define SCHED_UNDEF 0 +#define SCHED_LOTTERY 1 // Lottery scheduler +#define SCHED_RR_SIM 2 // Single Queue Round Robin +#define SCHED_RR_PRI 3 // Multi Queue Round Robin +// Set scheduler type +#define SCHEDULER_TYPE SCHED_LOTTERY + // === CONSTANTS === #define DEFAULT_QUANTUM 10 -#define DEFAULT_TICKETS 5 -#define MAX_TICKETS 10 +#define DEFAULT_PRIORITY 5 +#define MIN_PRIORITY 10 const enum eConfigTypes cCONFIG_TYPES[] = { CFGT_HEAPSTR, // e.g. CFG_VFS_CWD CFGT_INT, // e.g. CFG_VFS_MAXFILES @@ -23,23 +35,25 @@ extern void Proc_Start(void); extern tThread *Proc_GetCurThread(void); extern int Proc_Clone(Uint *Err, Uint Flags); extern void Proc_CallFaultHandler(tThread *Thread); +extern int GetCPUNum(void); // === PROTOTYPES === void Threads_Init(void); - int Threads_SetName(char *NewName); + int Threads_SetName(const char *NewName); char *Threads_GetName(int ID); -void Threads_SetTickets(int Num); +void Threads_SetPriority(tThread *Thread, int Pri); tThread *Threads_CloneTCB(Uint *Err, Uint Flags); int Threads_WaitTID(int TID, int *status); tThread *Threads_GetThread(Uint TID); void Threads_AddToDelete(tThread *Thread); -tThread *Threads_int_GetPrev(tThread **List, tThread *Thread); +tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread); void Threads_Exit(int TID, int Status); void Threads_Kill(tThread *Thread, int Status); void Threads_Yield(void); void Threads_Sleep(void); -void Threads_Wake(tThread *Thread); + int Threads_Wake(tThread *Thread); void Threads_AddActive(tThread *Thread); +tThread *Threads_RemActive(void); int Threads_GetPID(void); int Threads_GetTID(void); tUID Threads_GetUID(void); @@ -47,43 +61,45 @@ tUID Threads_GetUID(void); tGID Threads_GetGID(void); int Threads_SetGID(Uint *Errno, tUID ID); void Threads_Dump(void); +void Threads_DumpActive(void); +void Mutex_Acquire(tMutex *Mutex); +void Mutex_Release(tMutex *Mutex); + int Mutex_IsLocked(tMutex *Mutex); // === GLOBALS === // -- Core Thread -- // Only used for the core kernel tThread gThreadZero = { - NULL, 0, // Next, Lock - THREAD_STAT_ACTIVE, // Status - 0, // Exit Status - 0, 0, // TID, TGID - 0, 0, // UID, GID - 0, // Parent Thread ID - "ThreadZero", // Name - - 0, // Kernel Stack - {0}, // Saved State - {0}, // VM State - - 0, 0, // Current Fault, Fault Handler - - NULL, NULL, // Messages, Last Message - DEFAULT_QUANTUM, DEFAULT_QUANTUM, // Quantum, Remaining - DEFAULT_TICKETS, - {0} // Default config to zero + Status: THREAD_STAT_ACTIVE, // Status + ThreadName: "ThreadZero", // Name + Quantum: DEFAULT_QUANTUM, // Default Quantum + Remaining: DEFAULT_QUANTUM, // Current Quantum + Priority: DEFAULT_PRIORITY // Number of tickets }; // -- Processes -- // --- Locks --- -tSpinlock glThreadListLock = 0; ///\note NEVER use a heap function while locked +tShortSpinlock glThreadListLock; ///\note NEVER use a heap function while locked // --- Current State --- -volatile int giNumActiveThreads = 0; -//volatile int giTotalTickets = 0; -volatile int giFreeTickets = 0; -volatile Uint giNextTID = 1; +volatile int giNumActiveThreads = 0; // Number of threads on the active queue +volatile Uint giNextTID = 1; // Next TID to allocate // --- Thread Lists --- -tThread *gActiveThreads = NULL; // Currently Running Threads +tThread *gAllThreads = NULL; // All allocated threads tThread *gSleepingThreads = NULL; // Sleeping Threads tThread *gDeleteThreads = NULL; // Threads to delete - int giNumCPUs = 1; + int giNumCPUs = 1; // Number of CPUs +BOOL gaThreads_NoTaskSwitch[MAX_CPUS]; // Disables task switches for each core (Pseudo-IF) +// --- Scheduler Types --- +#if SCHEDULER_TYPE == SCHED_LOTTERY +const int caiTICKET_COUNTS[MIN_PRIORITY+1] = {100,81,64,49,36,25,16,9,4,1,0}; +volatile int giFreeTickets = 0; // Number of tickets held by non-scheduled threads +tThread *gActiveThreads = NULL; // Currently Running Threads +#elif SCHEDULER_TYPE == SCHED_RR_SIM +tThread *gActiveThreads = NULL; // Currently Running Threads +#elif SCHEDULER_TYPE == SCHED_RR_PRI +tThread *gaActiveThreads[MIN_PRIORITY+1]; // Active threads for each priority level +#else +# error "Unkown scheduler type" +#endif // === CODE === /** @@ -95,68 +111,107 @@ void Threads_Init(void) ArchThreads_Init(); // Create Initial Task + #if SCHEDULER_TYPE == SCHED_RR_PRI + gaActiveThreads[gThreadZero.Priority] = &gThreadZero; + #else gActiveThreads = &gThreadZero; - //giFreeTickets = gThreadZero.NumTickets; - giNumActiveThreads = 1; - - #if 1 - // Create Idle Task - if(Proc_Clone(0, 0) == 0) - { - tThread *cur = Proc_GetCurThread(); - cur->ThreadName = "Idle Thread"; - Threads_SetTickets(0); // Never called randomly - cur->Quantum = 1; // 1 slice quantum - for(;;) HALT(); // Just yeilds - } #endif + gAllThreads = &gThreadZero; + giNumActiveThreads = 1; + Proc_Start(); } /** - * \fn void Threads_SetName(char *NewName) + * \fn void Threads_SetName(const char *NewName) * \brief Sets the current thread's name + * \param NewName New name for the thread + * \return Boolean Failure */ -int Threads_SetName(char *NewName) +int Threads_SetName(const char *NewName) { tThread *cur = Proc_GetCurThread(); - if( IsHeap(cur->ThreadName) ) - free( cur->ThreadName ); - // TODO: Possible concurrency issue - cur->ThreadName = malloc(strlen(NewName)+1); - strcpy(cur->ThreadName, NewName); + char *oldname = cur->ThreadName; + + // NOTE: There is a possibility of non-thread safety here + // A thread could read the current name pointer before it is zeroed + + cur->ThreadName = NULL; + + if( IsHeap(oldname) ) free( oldname ); + + cur->ThreadName = strdup(NewName); return 0; } /** * \fn char *Threads_GetName(int ID) * \brief Gets a thread's name + * \param ID Thread ID (-1 indicates current thread) + * \return Pointer to name + * \retval NULL Failure */ -char *Threads_GetName(int ID) +char *Threads_GetName(tTID ID) { if(ID == -1) { return Proc_GetCurThread()->ThreadName; } - // TODO: Find a thread and get its name - return NULL; + return Threads_GetThread(ID)->ThreadName; } /** - * \fn void Threads_SetTickets(int Num) - * \brief Sets the 'priority' of a task + * \fn void Threads_SetPriority(tThread *Thread, int Pri) + * \brief Sets the priority of a task + * \param Thread Thread to update ticket count (NULL means current thread) + * \param Pri New priority */ -void Threads_SetTickets(int Num) +void Threads_SetPriority(tThread *Thread, int Pri) { - tThread *cur = Proc_GetCurThread(); - if(Num < 0) return; - if(Num > MAX_TICKETS) Num = MAX_TICKETS; - - cur->NumTickets = Num; + // Get current thread + if(Thread == NULL) Thread = Proc_GetCurThread(); + // Bounds checking + // - If < 0, set to lowest priority + if(Pri < 0) Pri = MIN_PRIORITY; + if(Pri > MIN_PRIORITY) Pri = MIN_PRIORITY; + + // Do we actually have to do anything? + if( Pri == Thread->Priority ) return; + + #if SCHEDULER_TYPE == SCHED_RR_PRI + SHORTLOCK( &glThreadListLock ); + // Remove from old priority + Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread ); + // And add to new + Thread->Next = gaActiveThreads[Pri]; + gaActiveThreads[Pri] = Thread; + Thread->Priority = Pri; + SHORTREL( &glThreadListLock ); + #else + // If this isn't the current thread, we need to lock + if( Thread != Proc_GetCurThread() ) + { + SHORTLOCK( &glThreadListLock ); + + #if SCHEDULER_TYPE == SCHED_LOTTERY + giFreeTickets -= caiTICKET_COUNTS[Thread->Priority] - caiTICKET_COUNTS[Pri]; + # if DEBUG_TRACE_TICKETS + Log("Threads_SetTickets: new giFreeTickets = %i", giFreeTickets); + # endif + #endif + Thread->Priority = Pri; + SHORTREL( &glThreadListLock ); + } + else + Thread->Priority = Pri; + #endif } /** * \fn tThread *Threads_CloneTCB(Uint *Err, Uint Flags) + * \brief Clone the TCB of the current thread + * \param Err Error pointer + * \param Flags Flags for something... (What is this for?) */ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) { @@ -164,6 +219,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) int i; cur = Proc_GetCurThread(); + // Allocate and duplicate new = malloc(sizeof(tThread)); if(new == NULL) { *Err = -ENOMEM; @@ -173,13 +229,13 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) new->CurCPU = -1; new->Next = NULL; - new->IsLocked = 0; - new->Status = THREAD_STAT_ACTIVE; + memset( &new->IsLocked, 0, sizeof(new->IsLocked)); + new->Status = THREAD_STAT_PREINIT; new->RetStatus = 0; // Get Thread ID new->TID = giNextTID++; - new->PTID = cur->TID; + new->Parent = cur; // Clone Name new->ThreadName = strdup(cur->ThreadName); @@ -196,7 +252,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) // Set State new->Remaining = new->Quantum = cur->Quantum; - new->NumTickets = cur->NumTickets; + new->Priority = cur->Priority; // Set Signal Handlers new->CurFaultNum = 0; @@ -218,42 +274,54 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) } } + // Maintain a global list of threads + SHORTLOCK( &glThreadListLock ); + new->GlobalPrev = NULL; // Protect against bugs + new->GlobalNext = gAllThreads; + gAllThreads = new; + SHORTREL( &glThreadListLock ); + return new; } /** - * \fn Uint *Threads_GetCfgPtr(int Id) + * \brief Get a configuration pointer from the Per-Thread data area + * \param ID Config slot ID + * \return Pointer at ID */ -Uint *Threads_GetCfgPtr(int Id) +Uint *Threads_GetCfgPtr(int ID) { - if(Id < 0 || Id >= NUM_CFG_ENTRIES) { - Warning("Threads_GetCfgPtr: Index %i is out of bounds", Id); + if(ID < 0 || ID >= NUM_CFG_ENTRIES) { + Warning("Threads_GetCfgPtr: Index %i is out of bounds", ID); return NULL; } - return &Proc_GetCurThread()->Config[Id]; + return &Proc_GetCurThread()->Config[ID]; } /** - * \fn void Threads_WaitTID(int TID, int *status) * \brief Wait for a task to change state + * \param TID Thread ID to wait on (-1: Any child thread, 0: Any Child/Sibling, <-1: -PID) + * \param Status Thread return status + * \return TID of child that changed state */ -int Threads_WaitTID(int TID, int *status) +tTID Threads_WaitTID(int TID, int *Status) { // Any Child if(TID == -1) { - + Log_Error("Threads", "TODO: Threads_WaitTID(TID=-1) - Any Child"); return -1; } // Any peer/child thread if(TID == 0) { - + Log_Error("Threads", "TODO: Threads_WaitTID(TID=0) - Any Child/Sibling"); return -1; } // TGID = abs(TID) if(TID < -1) { + Log_Error("Threads", "TODO: Threads_WaitTID(TID<0) - TGID"); return -1; } @@ -261,24 +329,34 @@ int Threads_WaitTID(int TID, int *status) if(TID > 0) { tThread *t = Threads_GetThread(TID); int initStatus = t->Status; - int ret; + tTID ret; + // Wait for the thread to die! if(initStatus != THREAD_STAT_ZOMBIE) { - while(t->Status == initStatus) { - Threads_Yield(); + // TODO: Handle child also being suspended if wanted + while(t->Status != THREAD_STAT_ZOMBIE) { + Threads_Sleep(); + Log_Debug("Threads", "%i waiting for %i, t->Status = %i", + Threads_GetTID(), t->TID, t->Status); } } - ret = t->RetStatus; + // Set return status + Log_Debug("Threads", "%i waiting for %i, t->Status = %i", + Threads_GetTID(), t->TID, t->Status); + ret = t->TID; switch(t->Status) { case THREAD_STAT_ZOMBIE: + // Kill the thread t->Status = THREAD_STAT_DEAD; - if(status) *status = 0; + // TODO: Child return value? + if(Status) *Status = t->RetStatus; + // add to delete queue Threads_AddToDelete( t ); break; default: - if(status) *status = -1; + if(Status) *Status = -1; break; } return ret; @@ -288,42 +366,36 @@ int Threads_WaitTID(int TID, int *status) } /** - * \fn tThread *Threads_GetThread(Uint TID) * \brief Gets a thread given its TID * \param TID Thread ID + * \return Thread pointer */ tThread *Threads_GetThread(Uint TID) { tThread *thread; - // Search Active List - for(thread = gActiveThreads; + // Search global list + for(thread = gAllThreads; thread; - thread = thread->Next) - { - if(thread->TID == TID) - return thread; - } - - // Search Sleeping List - for(thread = gSleepingThreads; - thread; - thread = thread->Next) + thread = thread->GlobalNext) { if(thread->TID == TID) return thread; } + + Log("Unable to find TID %i on main list\n", TID); return NULL; } /** - * \fn void Threads_AddToDelete(tThread *Thread) * \brief Adds a thread to the delete queue + * \param Thread Thread to delete */ void Threads_AddToDelete(tThread *Thread) { // Add to delete queue + // TODO: Is locking needed? if(gDeleteThreads) { Thread->Next = gDeleteThreads; gDeleteThreads = Thread; @@ -334,31 +406,42 @@ void Threads_AddToDelete(tThread *Thread) } /** - * \fn tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) - * \brief Gets the previous entry in a thead linked list + * \brief Deletes an entry from a list + * \param List Pointer to the list head + * \param Thread Thread to find + * \return \a Thread */ -tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) +tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread) { - tThread *ret; - // First Entry - if(*List == Thread) { - return (tThread*)List; - } else { - for(ret = *List; - ret->Next && ret->Next != Thread; - ret = ret->Next - ); - // Error if the thread is not on the list - if(!ret->Next || ret->Next != Thread) { - return NULL; - } + tThread *ret, *prev = NULL; + + for(ret = *List; + ret && ret != Thread; + prev = ret, ret = ret->Next + ); + + // Is the thread on the list + if(!ret) { + //LogF("%p(%s) is not on list %p\n", Thread, Thread->ThreadName, List); + return NULL; } - return ret; + + if( !prev ) { + *List = Thread->Next; + //LogF("%p(%s) removed from head of %p\n", Thread, Thread->ThreadName, List); + } + else { + prev->Next = Thread->Next; + //LogF("%p(%s) removed from %p (prev=%p)\n", Thread, Thread->ThreadName, List, prev); + } + + return Thread; } /** - * \fn void Threads_Exit(int TID, int Status) - * \brief Exit the current process + * \brief Exit the current process (or another?) + * \param TID Thread ID to kill + * \param Status Exit status */ void Threads_Exit(int TID, int Status) { @@ -366,9 +449,9 @@ void Threads_Exit(int TID, int Status) Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF ); else Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF ); + // Halt forever, just in case - for(;;) - HALT(); + for(;;) HALT(); } /** @@ -379,13 +462,13 @@ void Threads_Exit(int TID, int Status) */ void Threads_Kill(tThread *Thread, int Status) { - tThread *prev; tMsg *msg; - // Kill all children + // TODO: Kill all children #if 0 { tThread *child; + // TODO: I should keep a .Parent pointer, and a .Children list for(child = gActiveThreads; child; child = child->Next) @@ -399,17 +482,7 @@ void Threads_Kill(tThread *Thread, int Status) ///\note Double lock is needed due to overlap of lock areas // Lock thread (stop us recieving messages) - LOCK( &Thread->IsLocked ); - - // Lock thread list - LOCK( &glThreadListLock ); - - // Get previous thread on list - prev = Threads_int_GetPrev( &gActiveThreads, Thread ); - if(!prev) { - Warning("Proc_Exit - Current thread is not on the active queue"); - return; - } + SHORTLOCK( &Thread->IsLocked ); // Clear Message Queue while( Thread->Messages ) @@ -419,43 +492,69 @@ void Threads_Kill(tThread *Thread, int Status) Thread->Messages = msg; } + // Lock thread list + SHORTLOCK( &glThreadListLock ); + + // Delete from active list + #if SCHEDULER_TYPE == SCHED_RR_PRI + if( !Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread ) ) + #else + if( !Threads_int_DelFromQueue( &gActiveThreads, Thread ) ) + #endif + { + Warning("Proc_Exit - Current thread is not on the active queue"); + SHORTREL( &glThreadListLock ); + SHORTREL( &Thread->IsLocked ); + return; + } + + // Ensure that we are not rescheduled Thread->Remaining = 0; // Clear Remaining Quantum Thread->Quantum = 0; // Clear Quantum to indicate dead thread - prev->Next = Thread->Next; // Remove from active + // Update bookkeeping giNumActiveThreads --; + #if SCHEDULER_TYPE == SCHED_LOTTERY if( Thread != Proc_GetCurThread() ) - giFreeTickets -= Thread->NumTickets; + giFreeTickets -= caiTICKET_COUNTS[ Thread->Priority ]; + #endif - // Mark thread as a zombie + // Save exit status Thread->RetStatus = Status; - // Don't Zombie if we are being killed as part of a tree + // Don't Zombie if we are being killed because our parent is if(Status == -1) { Thread->Status = THREAD_STAT_DEAD; Threads_AddToDelete( Thread ); } else { Thread->Status = THREAD_STAT_ZOMBIE; + // Wake parent + Threads_Wake( Thread->Parent ); } - // Release spinlocks - RELEASE( &Thread->IsLocked ); // Released first so that it IS released - RELEASE( &glThreadListLock ); + Log("Thread %i went *hurk* (%i)", Thread->TID, Thread->Status); - //Log("Thread %i went *hurk*", Thread->TID); + // Release spinlocks + SHORTREL( &glThreadListLock ); + SHORTREL( &Thread->IsLocked ); // TODO: We may not actually be released... - if(Status != -1) HALT(); + // And, reschedule + if(Status != -1) { + for( ;; ) + HALT(); + } } /** - * \fn void Threads_Yield(void) - * \brief Yield remainder of timeslice + * \brief Yield remainder of the current thread's timeslice */ void Threads_Yield(void) { - Proc_GetCurThread()->Remaining = 0; - HALT(); + tThread *thread = Proc_GetCurThread(); + thread->Remaining = 0; + //while(thread->Remaining == 0) + HALT(); } /** @@ -465,110 +564,174 @@ void Threads_Yield(void) void Threads_Sleep(void) { tThread *cur = Proc_GetCurThread(); - tThread *thread; - - //Log_Log("Threads", "%i going to sleep", cur->TID); // Acquire Spinlock - LOCK( &glThreadListLock ); - - // Get thread before current thread - thread = Threads_int_GetPrev( &gActiveThreads, cur ); - if(!thread) { - Warning("Threads_Sleep - Current thread is not on the active queue"); - Threads_Dump(); - RELEASE( &glThreadListLock ); - return; - } + SHORTLOCK( &glThreadListLock ); // Don't sleep if there is a message waiting if( cur->Messages ) { - RELEASE( &glThreadListLock ); + SHORTREL( &glThreadListLock ); return; } - // Unset remaining timeslices (force a task switch on timer fire) - cur->Remaining = 0; - - // Remove from active list - thread->Next = cur->Next; + // Remove us from running queue + Threads_RemActive(); + // Mark thread as sleeping + cur->Status = THREAD_STAT_SLEEPING; // Add to Sleeping List (at the top) cur->Next = gSleepingThreads; gSleepingThreads = cur; - // Reduce the active count & ticket count - giNumActiveThreads --; - //giTotalTickets -= cur->NumTickets; - // Mark thread as sleeping - cur->Status = THREAD_STAT_SLEEPING; + #if DEBUG_TRACE_STATE + Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName); + #endif // Release Spinlock - RELEASE( &glThreadListLock ); + SHORTREL( &glThreadListLock ); while(cur->Status != THREAD_STAT_ACTIVE) HALT(); } /** - * \fn void Threads_Wake( tThread *Thread ) + * \fn int Threads_Wake( tThread *Thread ) * \brief Wakes a sleeping/waiting thread up + * \param Thread Thread to wake + * \return Boolean Failure (Returns ERRNO) + * \warning This should ONLY be called with task switches disabled */ -void Threads_Wake(tThread *Thread) +int Threads_Wake(tThread *Thread) { - tThread *prev; + if(!Thread) + return -EINVAL; + switch(Thread->Status) { - case THREAD_STAT_ACTIVE: break; + case THREAD_STAT_ACTIVE: + Log("Thread_Wake: Waking awake thread (%i)", Thread->TID); + return -EALREADY; + case THREAD_STAT_SLEEPING: - //Log_Log("Threads", "Waking %i (%p) from sleeping", Thread->TID, Thread); - LOCK( &glThreadListLock ); - prev = Threads_int_GetPrev(&gSleepingThreads, Thread); - prev->Next = Thread->Next; // Remove from sleeping queue - Thread->Next = gActiveThreads; // Add to active queue - gActiveThreads = Thread; - giNumActiveThreads ++; - // Thread can't be the current, so no need to check - giFreeTickets += Thread->NumTickets; - Thread->Status = THREAD_STAT_ACTIVE; - RELEASE( &glThreadListLock ); - break; + SHORTLOCK( &glThreadListLock ); + // Remove from sleeping queue + Threads_int_DelFromQueue(&gSleepingThreads, Thread); + + Threads_AddActive( Thread ); + + #if DEBUG_TRACE_STATE + Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName); + #endif + SHORTREL( &glThreadListLock ); + return -EOK; + case THREAD_STAT_WAITING: Warning("Thread_Wake - Waiting threads are not currently supported"); - break; + return -ENOTIMPL; + case THREAD_STAT_DEAD: Warning("Thread_Wake - Attempt to wake dead thread (%i)", Thread->TID); - break; + return -ENOTIMPL; + default: Warning("Thread_Wake - Unknown process status (%i)\n", Thread->Status); - break; + return -EINTERNAL; } } /** * \brief Wake a thread given the TID + * \param TID Thread ID to wake + * \return Boolean Faulure (errno) */ -void Threads_WakeTID(tTID Thread) +int Threads_WakeTID(tTID TID) { - Threads_Wake( Threads_GetThread(Thread) ); + tThread *thread = Threads_GetThread(TID); + int ret; + if(!thread) + return -ENOENT; + ret = Threads_Wake( thread ); + //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread); + return ret; } /** - * \fn void Threads_AddActive(tThread *Thread) * \brief Adds a thread to the active queue */ void Threads_AddActive(tThread *Thread) { - LOCK( &glThreadListLock ); + SHORTLOCK( &glThreadListLock ); + + if( Thread->Status == THREAD_STAT_ACTIVE ) { + tThread *cur = Proc_GetCurThread(); + Warning("WTF, CPU%i %p (%i %s) is adding %p (%i %s) when it is active", + GetCPUNum(), cur, cur->TID, cur->ThreadName, Thread, Thread->TID, Thread->ThreadName); + } + + // Set state + Thread->Status = THREAD_STAT_ACTIVE; + Thread->CurCPU = -1; + // Add to active list + #if SCHEDULER_TYPE == SCHED_RR_PRI + Thread->Next = gaActiveThreads[Thread->Priority]; + gaActiveThreads[Thread->Priority] = Thread; + #else Thread->Next = gActiveThreads; gActiveThreads = Thread; + #endif + + // Update bookkeeping giNumActiveThreads ++; - // Thread can't be the current, so no need to check - giFreeTickets += Thread->NumTickets; - //Log("Threads_AddActive: giNumActiveThreads = %i, giTotalTickets = %i", - // giNumActiveThreads, giTotalTickets); - RELEASE( &glThreadListLock ); + + #if SCHEDULER_TYPE == SCHED_LOTTERY + giFreeTickets += caiTICKET_COUNTS[ Thread->Priority ]; + # if DEBUG_TRACE_TICKETS + Log("Threads_AddActive: CPU%i %p %i (%s) added, new giFreeTickets = %i", + GetCPUNum(), Thread, Thread->TID, Thread->ThreadName, giFreeTickets); + # endif + #endif + + SHORTREL( &glThreadListLock ); +} + +/** + * \brief Removes the current thread from the active queue + * \warning This should ONLY be called with task switches disabled + * \return Current thread pointer + */ +tThread *Threads_RemActive(void) +{ + tThread *ret = Proc_GetCurThread(); + + SHORTLOCK( &glThreadListLock ); + + // Delete from active queue + #if SCHEDULER_TYPE == SCHED_RR_PRI + if( !Threads_int_DelFromQueue(&gaActiveThreads[ret->Priority], ret) ) + #else + if( !Threads_int_DelFromQueue(&gActiveThreads, ret) ) + #endif + { + SHORTREL( &glThreadListLock ); + return NULL; + } + + ret->Next = NULL; + ret->Remaining = 0; + ret->CurCPU = -1; + + giNumActiveThreads --; + // no need to decrement tickets, scheduler did it for us + + #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS + Log("Threads_RemActive: CPU%i %p %i (%s) removed, giFreeTickets = %i", + GetCPUNum(), ret, ret->TID, ret->ThreadName, giFreeTickets); + #endif + + SHORTREL( &glThreadListLock ); + + return ret; } /** @@ -577,7 +740,7 @@ void Threads_AddActive(tThread *Thread) */ void Threads_SetFaultHandler(Uint Handler) { - Log_Log("Threads", "Threads_SetFaultHandler: Handler = %p", Handler); + //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler); Proc_GetCurThread()->FaultHandler = Handler; } @@ -643,7 +806,7 @@ int Threads_SetUID(Uint *Errno, tUID ID) *Errno = -EACCES; return -1; } - Log("Threads_SetUID - Setting User ID to %i", ID); + Log_Debug("Threads", "TID %i's UID set to %i", t->TID, ID); t->UID = ID; return 0; } @@ -655,41 +818,77 @@ int Threads_SetGID(Uint *Errno, tGID ID) *Errno = -EACCES; return -1; } - Log("Threads_SetGID - Setting Group ID to %i", ID); + Log_Debug("Threads", "TID %i's GID set to %i", t->TID, ID); t->GID = ID; return 0; } /** * \fn void Threads_Dump(void) - * \brief Dums a list of currently running threads */ -void Threads_Dump(void) +void Threads_DumpActive(void) { tThread *thread; - tThread *cur = Proc_GetCurThread(); + #if SCHEDULER_TYPE == SCHED_RR_PRI + int i; + #endif - Log("Active Threads:"); - for(thread=gActiveThreads;thread;thread=thread->Next) + Log("Active Threads: (%i reported)", giNumActiveThreads); + + #if SCHEDULER_TYPE == SCHED_RR_PRI + for( i = 0; i < MIN_PRIORITY+1; i++ ) { - Log(" %i (%i) - %s (CPU %i)", - thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); - Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum); - Log(" KStack 0x%x", thread->KernelStack); + for(thread=gaActiveThreads[i];thread;thread=thread->Next) + #else + for(thread=gActiveThreads;thread;thread=thread->Next) + #endif + { + Log(" %p %i (%i) - %s (CPU %i)", + thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); + if(thread->Status != THREAD_STAT_ACTIVE) + Log(" ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE); + Log(" Priority %i, Quantum %i", thread->Priority, thread->Quantum); + Log(" KStack 0x%x", thread->KernelStack); + } + + #if SCHEDULER_TYPE == SCHED_RR_PRI } - Log("Sleeping Threads:"); - for(thread=gSleepingThreads;thread;thread=thread->Next) + #endif +} + +/** + * \fn void Threads_Dump(void) + * \brief Dumps a list of currently running threads + */ +void Threads_Dump(void) +{ + tThread *thread; + + Log("--- Thread Dump ---"); + Threads_DumpActive(); + + Log("All Threads:"); + for(thread=gAllThreads;thread;thread=thread->GlobalNext) { - Log("%c%i (%i) - %s", - (thread==cur?'*':' '), - thread->TID, thread->TGID, thread->ThreadName); - Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum); + Log(" %p %i (%i) - %s (CPU %i)", + thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); + Log(" State %i (%s)", thread->Status, casTHREAD_STAT[thread->Status]); + switch(thread->Status) + { + case THREAD_STAT_MUTEXSLEEP: + Log(" Mutex Pointer: %p", thread->WaitPointer); + break; + case THREAD_STAT_ZOMBIE: + Log(" Return Status: %i", thread->RetStatus); + break; + default: break; + } + Log(" Priority %i, Quantum %i", thread->Priority, thread->Quantum); Log(" KStack 0x%x", thread->KernelStack); } } /** - * \fn tThread *Threads_GetNextToRun(int CPU, tThread *Last) * \brief Gets the next thread to run * \param CPU Current CPU * \param Last The thread the CPU was running @@ -697,73 +896,210 @@ void Threads_Dump(void) tThread *Threads_GetNextToRun(int CPU, tThread *Last) { tThread *thread; - int ticket; - int number; - // Note: Enable the code to tell if the switch code has the lock, or - // if it's the other code. + // If this CPU has the lock, we must let it complete + if( CPU_HAS_LOCK( &glThreadListLock ) ) + return Last; - // Check if the thread list is locked by other code - // - If so, don't switch (give it a chance to complete) - if( IS_LOCKED(&glThreadListLock) ) + // Don't change threads if the current CPU has switches disabled + if( gaThreads_NoTaskSwitch[CPU] ) return Last; + + + // Lock thread list + SHORTLOCK( &glThreadListLock ); + + // Clear Delete Queue + // - I should probably put this in a worker thread to avoid calling free() in the scheduler + while(gDeleteThreads) + { + thread = gDeleteThreads->Next; + if( IS_LOCKED(&gDeleteThreads->IsLocked) ) { // Only free if structure is unused + // Set to dead + gDeleteThreads->Status = THREAD_STAT_BURIED; + // Free name + if( IsHeap(gDeleteThreads->ThreadName) ) + free(gDeleteThreads->ThreadName); + // Remove from global list + if( gDeleteThreads == gAllThreads ) + gAllThreads = gDeleteThreads->GlobalNext; + else + gDeleteThreads->GlobalPrev->GlobalNext = gDeleteThreads->GlobalNext; + free( gDeleteThreads ); + } + gDeleteThreads = thread; + } // No active threads, just take a nap if(giNumActiveThreads == 0) { + SHORTREL( &glThreadListLock ); + #if DEBUG_TRACE_TICKETS + Log("No active threads"); + #endif return NULL; } - // Lock thread list - // - HLT lock (Used because only another CPU can obtain the lock, - // but it has a potentially long lock period) - // - Well, this CPU can obtain the lock, but that is aliveviated by - // the above. - TIGHTLOCK( &glThreadListLock ); - + #if SCHEDULER_TYPE != SCHED_RR_PRI // Special case: 1 thread if(giNumActiveThreads == 1) { if( gActiveThreads->CurCPU == -1 ) gActiveThreads->CurCPU = CPU; - RELEASE( &glThreadListLock ); + + SHORTREL( &glThreadListLock ); + if( gActiveThreads->CurCPU == CPU ) return gActiveThreads; + return NULL; // CPU has nothing to do } + #endif // Allow the old thread to be scheduled again if( Last ) { - if( Last->Status == THREAD_STAT_ACTIVE ) - giFreeTickets += Last->NumTickets; + if( Last->Status == THREAD_STAT_ACTIVE ) { + #if SCHEDULER_TYPE == SCHED_LOTTERY + giFreeTickets += caiTICKET_COUNTS[ Last->Priority ]; + # if DEBUG_TRACE_TICKETS + LogF(" CPU %i released %p (%i %s) into the pool (%i tickets in pool)\n", + CPU, Last, Last->TID, Last->ThreadName, giFreeTickets); + # endif + #endif + } + #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS + else + LogF(" CPU %i released %p (%i %s)->Status = %i (Released)\n", + CPU, Last, Last->TID, Last->ThreadName, Last->Status); + #endif Last->CurCPU = -1; } - - // Get the ticket number - ticket = number = rand() % giFreeTickets; - // Find the next thread - for(thread=gActiveThreads;thread;thread=thread->Next) - { - if(thread->CurCPU >= 0) continue; - if(thread->NumTickets > number) break; - number -= thread->NumTickets; - } - // Error Check - if(thread == NULL) + // --- + // Lottery Scheduler + // --- + #if SCHEDULER_TYPE == SCHED_LOTTERY { + int ticket, number; + # if 1 number = 0; - for(thread=gActiveThreads;thread;thread=thread->Next) { + for(thread = gActiveThreads; thread; thread = thread->Next) { + if(thread->CurCPU >= 0) continue; + if(thread->Status != THREAD_STAT_ACTIVE) + Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i", + thread, thread->TID, thread->ThreadName, thread->Status); + if(thread->Next == thread) { + Panic("Bookkeeping fail - %p %i(%s) loops back on itself", + thread, thread->TID, thread->ThreadName, thread->Status); + } + number += caiTICKET_COUNTS[ thread->Priority ]; + } + if(number != giFreeTickets) { + Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i", + giFreeTickets, number, CPU); + } + # endif + + // No free tickets (all tasks delegated to cores) + if( giFreeTickets == 0 ) { + SHORTREL(&glThreadListLock); + return NULL; + } + + // Get the ticket number + ticket = number = rand() % giFreeTickets; + + // Find the next thread + for(thread=gActiveThreads;thread;thread=thread->Next) + { if(thread->CurCPU >= 0) continue; - number += thread->NumTickets; + if( caiTICKET_COUNTS[ thread->Priority ] > number) break; + number -= caiTICKET_COUNTS[ thread->Priority ]; + } + + // If we didn't find a thread, something went wrong + if(thread == NULL) + { + number = 0; + for(thread=gActiveThreads;thread;thread=thread->Next) { + if(thread->CurCPU >= 0) continue; + number += caiTICKET_COUNTS[ thread->Priority ]; + } + Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)", + giFreeTickets, number); + } + # if DEBUG_TRACE_TICKETS + LogF(" CPU%i giFreeTickets = %i, running %p (%i %s CPU=%i)\n", + CPU, giFreeTickets, thread, thread->TID, thread->ThreadName, thread->CurCPU); + # endif + + giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ]; + } + + // --- + // Priority based round robin scheduler + // --- + #elif SCHEDULER_TYPE == SCHED_RR_PRI + { + int i; + for( i = 0; i < MIN_PRIORITY + 1; i ++ ) + { + for(thread = gaActiveThreads[i]; thread; thread = thread->Next) + { + if( thread->CurCPU == -1 ) break; + } + // If we fall onto the same queue again, special handling is + // needed + if( i == Last->Priority ) { + tThread *savedThread = thread; + + // Find the next unscheduled thread in the list + for( thread = Last->Next; thread; thread = thread->Next ) + { + if( thread->CurCPU == -1 ) break; + } + // If we don't find anything after, just use the one + // found above. + if( !thread ) thread = savedThread; + } + // Found a thread? Schedule it! + if( thread ) break; + } + + // Anything to do? + if( !thread ) { + SHORTREL(&glThreadListLock); + return NULL; + } + } + #elif SCHEDULER_TYPE == SCHED_RR_SIM + { + // Find the next unscheduled thread in the list + for( thread = Last->Next; thread; thread = thread->Next ) + { + if( thread->CurCPU == -1 ) break; + } + // If we don't find anything after, search from the beginning + if( !thread ) + { + for(thread = gActiveThreads; thread; thread = thread->Next) + { + if( thread->CurCPU == -1 ) break; + } + } + + // Anything to do? + if( !thread ) { + SHORTREL(&glThreadListLock); + return NULL; } - Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)", - giFreeTickets, number); } + #else + # error "Unimplemented scheduling algorithm" + #endif // Make the new thread non-schedulable - giFreeTickets -= thread->NumTickets; thread->CurCPU = CPU; - RELEASE( &glThreadListLock ); + SHORTREL( &glThreadListLock ); return thread; } @@ -779,5 +1115,121 @@ void Threads_SegFault(tVAddr Addr) //Threads_Exit( 0, -1 ); } +/** + * \brief Acquire a heavy mutex + * \param Mutex Mutex to acquire + * + * This type of mutex checks if the mutex is avaliable, and acquires it + * if it is. Otherwise, the current thread is added to the mutex's wait + * queue and the thread suspends. When the holder of the mutex completes, + * the oldest thread (top thread) on the queue is given the lock and + * restarted. + */ +void Mutex_Acquire(tMutex *Mutex) +{ + tThread *us = Proc_GetCurThread(); + + // Get protector + SHORTLOCK( &Mutex->Protector ); + + //Log("Mutex_Acquire: (%p)", Mutex); + + // Check if the lock is already held + if( Mutex->Owner ) { + SHORTLOCK( &glThreadListLock ); + // - Remove from active list + us = Threads_RemActive(); + us->Next = NULL; + // - Mark as sleeping + us->Status = THREAD_STAT_MUTEXSLEEP; + us->WaitPointer = Mutex; + + // - Add to waiting + if(Mutex->LastWaiting) { + Mutex->LastWaiting->Next = us; + Mutex->LastWaiting = us; + } + else { + Mutex->Waiting = us; + Mutex->LastWaiting = us; + } + #if 0 + { + int i = 0; + tThread *t; + for( t = Mutex->Waiting; t; t = t->Next, i++ ) + Log("[%i] (tMutex)%p->Waiting[%i] = %p (%i %s)", us->TID, Mutex, i, + t, t->TID, t->ThreadName); + } + #endif + + SHORTREL( &glThreadListLock ); + SHORTREL( &Mutex->Protector ); + while(us->Status == THREAD_STAT_MUTEXSLEEP) Threads_Yield(); + // We're only woken when we get the lock + us->WaitPointer = NULL; + } + // Ooh, let's take it! + else { + Mutex->Owner = us; + SHORTREL( &Mutex->Protector ); + } + + #if 0 + extern tMutex glPhysAlloc; + if( Mutex != &glPhysAlloc ) + LogF("Mutex %p taken by %i %p\n", Mutex, us->TID, __builtin_return_address(0)); + #endif +} + +/** + * \brief Release a held mutex + * \param Mutex Mutex to release + */ +void Mutex_Release(tMutex *Mutex) +{ + SHORTLOCK( &Mutex->Protector ); + //Log("Mutex_Release: (%p)", Mutex); + if( Mutex->Waiting ) { + Mutex->Owner = Mutex->Waiting; // Set owner + Mutex->Waiting = Mutex->Waiting->Next; // Next! + // Reset ->LastWaiting to NULL if we have just removed the last waiting thread + // 2010-10-02 21:50 - Comemerating the death of the longest single + // blocker in the Acess2 history. REMEMBER TO + // FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT + if( Mutex->LastWaiting == Mutex->Owner ) + Mutex->LastWaiting = NULL; + + // Wake new owner + SHORTLOCK( &glThreadListLock ); + if( Mutex->Owner->Status != THREAD_STAT_ACTIVE ) + Threads_AddActive(Mutex->Owner); + SHORTREL( &glThreadListLock ); + } + else { + Mutex->Owner = NULL; + } + SHORTREL( &Mutex->Protector ); + + #if 0 + extern tMutex glPhysAlloc; + if( Mutex != &glPhysAlloc ) + LogF("Mutex %p released by %i %p\n", Mutex, Threads_GetTID(), __builtin_return_address(0)); + #endif +} + +/** + * \brief Is this mutex locked? + * \param Mutex Mutex pointer + */ +int Mutex_IsLocked(tMutex *Mutex) +{ + return Mutex->Owner != NULL; +} + // === EXPORTS === EXPORT(Threads_GetUID); +EXPORT(Threads_GetGID); +EXPORT(Mutex_Acquire); +EXPORT(Mutex_Release); +EXPORT(Mutex_IsLocked);